a)  x – 32 = − 5 − 17 ⇔ x – 32 = − 32 ⇔ x = − 32 + 32 ⇔ x = 0.

b)  16 – x = 21 – − 8 ⇔ 16 – x = 21 + 8 ⇔ 16 − x = 30 ⇔ − x = 30 − 16 ⇔ − x = 14 ⇔ x = − 14.

c)  106 − x = − 58 – 8 ⇔ 106 − x = − 66 ⇔ − x = − 66 − 106 ⇔ − x = − 172 ⇔ x = 172.

c) \(47-\left(x-15\right)=21\)

\(\Leftrightarrow x-15=47-21\)

\(\Leftrightarrow x-15=26\)

\(\Leftrightarrow x=26+15=41\)

d) \(-5-\left(24-x\right)=-11\)

\(\Leftrightarrow24-x=-5+11\)

\(\Leftrightarrow24-x=6\)

\(\Leftrightarrow x=24-6=18\)

a) 16-x=21+8

     16-x=29

          x=16-29

          x=-13

a) \(16-x=21-\left(-8\right)\)

\(\Leftrightarrow16-x=29\)

\(\Leftrightarrow x=16-29=-13\)

b) \(x-32=-5-17\)

\(\Leftrightarrow x-32=-22\)

\(\Leftrightarrow x=-22+32=10\)

a, x-32=(-5)-17

=>x-32=-22

=>x=(-22)+32

=>x=10

b,16-x=21-(-8)

=>16-x=29

=>x=16-29

=>x=-13

\(x-32=\left(-5\right)-17\)

\(x-32=-22\)

\(x=\left(-22\right)+32\)

\(x=10\)

\(16-x=21-\left(-8\right)\)

\(16-x=29\)

\(x=16-29\)

\(x=-13\)

a)  (2x-32):16=3

      2x-32=3.16

       2x-32=48

       2x=48+32

        2x=80

       x=80:2

       x=40

b) (7x -8:2):5=8

     (7x-4):5=8

      7x-4=8.5

       7x-4=40

      7x=40+4

a) (2x - 32) : 16 = 3 \(=\left(2x-32\right)=3.16=48\)

= \(\left(2x-32\right)=48\)

= \(2x=48+32=80\)

= \(2x=80\Rightarrow x=80:2=40\)

b) ( 7x - 8 :2) : 5 = 8 

= \(\left(7x-8:2\right)=8.5=40\)

= \(\left(7x-8:2\right)=40\)

= \(\left(7x-8\right)=40.2=80\)

= \(\left(7x-8\right)=80\)

= \(7x=80+8=88\)

=>x = 88 : 7 = ......

c) 215 + ( x - 21) : 2 = 235 

\(=\left(x-21\right):2=235-215=20\)

= \(\left(x-21\right):2=20\)

= \(\left(x-21\right)=20.2=40\) 

= \(\left(x-21\right)=40\)

= \(\Rightarrow x=40+21=61\)

a, ( 2x - 32 ) : 16 = 3

    ( 2x - 32 )       = 3 x 16

      2x - 32       =   48

      2x             =  48 + 32

      2x             =     80

       x             = 80 : 2

       x             =     40

b, ( 7x - 8 : 2 ) : 5 = 8

    ( 7x - 8 : 2 )     = 8 x 5

    ( 7x - 8 : 2 )     =   40

      7x x  4          =  40

      7x                 = 40 : 4

      7x                 =   10

       x                  =   10 : 7

c , 215 + ( x - 21 ) : 2  = 235

     215 + ( x - 21 )      = 235 x 2

     215 + ( x - 21 )      =    470

              ( x - 21 )      =  470 - 215

                x - 21         =      255

                x               =  255  + 21

                x               =      276

a)    \(\frac{3}{16}+\frac{4}{15}+\frac{5}{16}+\frac{1}{15}\)

\(=\left(\frac{3}{16}+\frac{5}{16}\right)+\left(\frac{4}{15}+\frac{1}{15}\right)\)

\(=\frac{1}{2}+\frac{1}{3}\)

\(=\frac{5}{6}\)

b)   \(\frac{6}{7}\times\frac{8}{15}\times\frac{7}{6}\times\frac{15}{16}\)

\(=\left(\frac{6}{7}\times\frac{7}{6}\right)\times\left(\frac{8}{15}\times\frac{15}{16}\right)\)

\(=1\times\frac{1}{2}=\frac{1}{2}\)

c)   \(\frac{19}{20}\times\frac{13}{21}+\frac{9}{20}\times\frac{8}{21}\)

\(=\frac{19\times13}{20\times21}+\frac{9\times8}{20\times21}\)

\(=\frac{247}{420}+\frac{72}{420}\)

\(=\frac{319}{420}\)

còn phần D đâu bn 

tích cho chị nha

 câu a)     = 5/6

 câu b = 1/2

 câu c = 319/420

2, 

a) \(315-\left(135-x\right)=215\)

\(\Rightarrow135-x=315-215\)

\(\Rightarrow135-x=100\)

\(\Rightarrow x=135-100\)

\(\Rightarrow x=35\)

b) \(x-320:32=25\cdot16\)

\(\Rightarrow x-10=5^2\cdot4^2\)

\(\Rightarrow x-10=20^2\)

\(\Rightarrow x-10=400\)

\(\Rightarrow x=410\)

c) \(3\cdot x-2018:2=23\)

\(=3\cdot x-1009=23\)

\(\Rightarrow3\cdot x=1032\)

\(\Rightarrow x=1032:3\)

\(\Rightarrow x=344\)

d) \(280-9\cdot x-x=80\)

\(\Rightarrow280-x\cdot\left(9+1\right)=80\)

\(\Rightarrow280-10\cdot x=80\)

\(\Rightarrow10\cdot x=280-80\)

\(\Rightarrow10\cdot x=200\)

\(\Rightarrow x=20\)

e) \(38\cdot x-12\cdot x-x\cdot16=40\)

\(\Rightarrow x\cdot\left(38-12-16\right)=40\)

\(\Rightarrow x\cdot10=40\)

\(\Rightarrow x=40:10\)

\(\Rightarrow x=4\)

bài 1 cậu ko giải giúp mình dc à

Bạn ơi bạn làm đc bao nhiêu thì làm phụ mình nhé 

bài1

a, 

5 - 7 + 3 +(-8)

= -2 + 3 + ( - 8)

=     1    + (-8)= -7

a; - (-5) - (+7) + (+3) + (-8)

  = 5 - 7 + 3  - 8

= (5 + 3 - 8) - 7

= (8 - 8) - 7

= 0 - 7

= - 7